1. Field of the Invention
The present invention relates to a four-cycle engine used for a vehicle such as a motorcycle, and more particularly to a joint structure for a cylinder head and a cylinder head cover of a four-cycle engine for a vehicle.
2. Description of the Background Art
A conventional four-cycle engine of the background art includes a double overhead camshaft (DOHC) having an intake valve and an exhaust valve driven by different camshafts. Japanese published unexamined patent application No. Hei1-132485, e.g., pp. 9 and 10, and FIGS. 4 and 5 of this document; and Japanese published unexamined patent application No. Hei9-287464, e.g., 0021 (identifier), and FIG. 2 of this document, each describe the above-described four-cycle engine arrangement. Specifically, a joint of a cylinder head and a cylinder head cover (hereinafter referred to as a head cover joint) is inclined toward the joint of the cylinder head and a cylinder block (hereinafter called a cylinder joint). Accordingly, the cylinder head can be decreased in size.
Japanese published unexamined patent application No. 2002-122007, e.g., FIG. 1 of this document, describes an engine of a single overhead camshaft (SOHC) type having an intake valve driven by one camshaft and an exhaust valve driven by the same (common) camshaft via a valve arm. In this type of engine, an engine hanger is provided below an intake port of a cylinder head, and the engine hanger supports a body frame.